International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk

Content and application

The IGC Code is mandatory under the SOLAS Convention, specifically Chapter VII. It applies to ships carrying liquefied gases with the characteristics described in the Code (listed in Chapter 19 of the 2016 edition) and has been in force since 1 July 1986.

Prior to 1986, older gas carriers constructed prior to 1 July 1986 comply with the requirements of the older Code for the Construction Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) and the Code for Existing Ships Carrying Liquefied Gases in Bulk (EGC Code).

The Code includes design and construction standards, and equipment requirements. The Code also covers technical subjects such as cargo tanks and cargo containment, ship arrangements, pressure vessels, vapour and pressure piping systems, materials, controls and instrumentation, venting, fire protection, filling limits and other special requirements. The Code also sets out requirements for emergency shutdown (ESD) systems for when liquefied gas cargoes are carried in bulk.

Section 4.1 of the IGC Code defines several types of tanks that can carry liquefied gases. These include independent tanks (of which there are three types, A, B and C), membrane tanks, integral tanks and semi-membrane tanks.